PREAMBLE: I wanted a lightweight 10" combo, but couldn't find a Princeton for less than $700. But I finally got one of the last SCXDs from MF, for cheap. This amp has a solid-state preamp with digital FX and modeling. Then the signal goes to the tube section, which is one half of a 12ax7 as a gain stage, the other half as a PI, and a pair of 6V6 as power section. As expected, the digital front end exhibits a lot of white noise, plus crappy digital artifacts and aliasing as notes decay into silence. Fine for loud rock, but poor for sensitive playing. I followed the lead of others <http://www.thegearpage.net/board/showthread.php?t=628217>, and installed a line-in jack just following the digital preamp. As I hoped, this cut all of the crappy noise from the preamp, and let me play directly into the tube stages. However, the signal from my guitar is obviously very low for this stage in an amp. It sounded nice and clean, but as if the Gain control was down around 1 or 2 (obviously, this mod bypasses all of the controls--I'm just trying to give an idea of the volume level). QUESTIONS: How much, in dB or mVac or something useful, does my guitar's signal need to be boosted to equate to the signal leaving the preamp of a dimed Princeton? I pulled out my mod, because I haven't drilled the chassis yet, so I can't test this idea: I just ordered an OCD pedal, which advertises 30dB of boost. Would that make a good preamp? Any other ideas for bypassing the crappy preamp and making this SCXD a poor-man's Princeton (while leaving said crappy preamp intact and available)?